We live in a world where one in six deaths are caused by easily curable infectious diseases; one in eight deaths stem from air pollution, mostly from cooking indoors with dung and twigs; and billions of people live in abject poverty, with no electricity and little food. We ought never to have entertained the notion that the world’s greatest challenge could be to reduce temperature rises in our generation by a fraction of a degree.

But poverty kills people too, and slow growth can cost politicians their jobs. Two decades of environmental worries are proving only a marginal constraint on the global coal industry. Some are trying to get out: in America Consol Energy is selling five mines in West Virginia to concentrate on shale gas. Big coal-burners such as American Electric Power and Duke Energy are shutting coal-fired plants. Yet despite America’s shale-gas boom, the federal Energy Information Administration reckons that by 2040 the country will still be generating 32% of its electricity from coal (compared with nearly 42% now).* The International Energy Agency has even predicted that, barring policy changes, coal may rival oil in importance by 2017. As countries get richer they tend to look for alternatives—China is scrambling to curb its rising consumption. But others, such as India and Africa, are set to take up the slack (see chart).